I'm having an issue with the Magic Action Box that I have added to my website.

The situation is that the email service that I have been using for years is Constant Contact. Because of this, in order to use that with the MAB, I have to make use of the Opt-In option, which I have. In doing that, I have added the HTML code into the "Opt-in Form Code" box (as instructed). I then clicked the "Process Code" button (as instructed).

Although the MAB does appear on my website pages, when adding an email into the box and pressing the "Subscribe" button, instead of processing the request, it instead takes you to a page that says "Page Not Found".